I guess this is the same reason Ai clocks are stuck on ten to two. In case of the clocks it is because ten to twolooks nice on a clock so most images will have it. Ai doesn’t understand how time corresponds to how a clock looks, just that something that looks like a clock has two lines there.

So since most depictions of wine glasses are half full, when you ask for a wine glass it will give you one that is half full. Fill level being somewhat irrelevant as it wasn’t part of the training data

Sorry, don’t exfoliate myself so no clue.

It looks like it is the acids (dehydroacetic acid and ascorbic acid) that do the exfoliating in this recipe.